is a bt data cable that connects my bt home hub to the main bt socket the same as a normal telephone cable as I need to move the hub and need a longer one
A quick 5 second look would soon tell you it's different, a telephone cable has a RJ11 plug one end and a BT plug the other end, the cable that goes between the ADSL filter and the hub will have a RJ11 on both ends.
How far do you want to move it and why? as the answers to these will enable us to say what the best solution is.
Make sure you get a good quality lead, as some have straight wires( not twisted as pairs) which will either slow or stop the broadband signal, so don't buy one from the £1 shop, get a proper modem lead cable, or buy some extension cable and a socket a fit a new socket nearer to where you want the computer.